[Coda]

Chaos Devil Dragon, Cyclone Devil Dragon, or Helheim would work too, for just dark resist.

Hades has dark resist and his uvos provide ATK bonuses to God or Devil. Chaos Venus likewise.

Dark Minerva would be an awesome choice, resist fire AND dark with a Devil-type ATK bonus.

Awoken Minerva resists dark and provides a much bigger ATK bonus to fire and dragon types. Likewise, Awoken Neptune gives a bonus to water and attacker, and Awoken Ceres gives a bonus to wood and balanced.

Dark-element Chester is another good choice if you run mono-dark.

In a pinch, Keeper of Gold is a not-TOO-terrible option. 20% reduction to all damage isn't as good as taking half damage or as good as a 2xHP/RCV leader for MOST things, but 20% reduction to all damage is noteworthy for being good for things that deal damage based on your max HP. Might or might not work out.